Australians with their eyes trained skyward may catch a glimpse of a “once-in-a-lifetime” stellar event in the coming months.
A pair of stars named T Coronae Borealis is set to explode, lighting up the southern hemisphere skies for the first time in 80 years.

T Coronae Borealis, also known as the Blaze Star, periodically undergoes something called a nova, where the star periodically bursts in brightness as it partially explodes.

A red giant star and white dwarf orbit each other in this animation of a nova similar to T Coronae Borealis. The red giant is a large sphere in shades of red, orange, and white, with the side facing the white dwarf the lightest shades. The white dwarf is hidden in a bright glow of white and yellows, which represent an accretion disk around the star. A stream of material, shown as a diffuse cloud of red, flows from the red giant to the white dwarf. (NASA/Goddard Space Flight Center)

”We can predict when this will happen based on the star’s brightness over time, and anytime over the next few months to two years, it could happen,” Melbourne astrophysicist Dr Sara Webb explained.

“It’s in the constellation Corona Borealis and if you keep an eye on that patch of sky you might notice when the ‘new star’ appears.”

The Coronae Borealis constellation is visible in Australia between May and September in the evening sky.

The constellation is 3000 light years away and usually only visible using a telescope.

However, when the Blaze Star explodes, it rapidly increases in brightness to around a magnitude +3, making it easily visible even in light-polluted areas.

It’s as if a brand new star appears in the night sky, before fading away a few nights later.

“It’s a once-in-a-lifetime event that will create a lot of new astronomers out there,” Dr Rebekah Hounsell, an assistant research scientist specialising in nova events at NASA’s Goddard Space Flight Centre, said.

“It’ll fuel the next generation of scientists.”

T Coronae Borealis is what is known as a white dwarf – a star whose internal fire has burnt out and is now essentially a dead star, which has been dramatically compressed.

The white dwarf is an Earth-sized remnant of a dead star with a mass comparable to that of our sun.

However, it is in orbit with another star – a red giant.

This causes an explosion which makes the white dwarf shine 1500 times brighter than usual, briefly lighting up our night sky.

“There are a few recurrent novae with very short cycles, but typically, we don’t often see a repeated outburst in a human lifetime, and rarely one so relatively close to our own system,” Hounsell said.

“It’s incredibly exciting to have this front-row seat.”